<?php

class LtDbSqlAdapterMysql implements LtDbSqlAdapter
{
    public function setCharset($charset)
    {
        return "SET NAMES " . str_replace('-', '', $charset);
    }

    public function setSchema($schema)
    {
        return "USE $schema";
    }

    public function showSchemas($database)
    {
        return "SHOW DATABASES";
    }

    public function showTables($schema)
    {
        return "SHOW TABLES";
    }

    public function showFields($table)
    {
        return "DESCRIBE $table";
    }

    public function beginTransaction()
    {
        return "START TRANSACTION";
    }

    public function commit()
    {
        return "COMMIT";
    }

    public function rollBack()
    {
        return "ROLLBACK";
    }

    public function limit($limit, $offset)
    {
        return " LIMIT $limit OFFSET $offset";
    }

    public function getSchemas($queryResult)
    {

    }

    public function getTables($queryResult)
    {

    }

    public function getFields($queryResult)
    {
        foreach ($queryResult as $key => $value) {
            $fields[$value['Field']]['name'] = $value['Field'];
            $fields[$value['Field']]['type'] = $value['Type'];
            /*
             * not null is NO or empty, null is YES
             */
            $fields[$value['Field']]['notnull'] = (bool)($value['Null'] != 'YES');
            $fields[$value['Field']]['default'] = $value['Default'];
            $fields[$value['Field']]['primary'] = (strtolower($value['Key']) == 'pri');
        }
        return $fields;
    }

    public function detectQueryType($sql)
    {
        if (preg_match("/^\s*SELECT|^\s*EXPLAIN|^\s*SHOW|^\s*DESCRIBE/i", $sql)) {
            $ret = 'SELECT';
        } else if (preg_match("/^\s*INSERT/i", $sql)) {
            $ret = 'INSERT';
        } else if (preg_match("/^\s*UPDATE|^\s*DELETE|^\s*REPLACE/i", $sql)) {
            $ret = 'CHANGE_ROWS';
        } else if (preg_match("/^\s*USE|^\s*SET/i", $sql)) {
            $ret = 'SET_SESSION_VAR';
        } else {
            $ret = 'OTHER';
        }
        return $ret;
    }
}